Publication date: 10th April 2024
All-solid-state batteries relying on Li metal as negative electrode material and a ceramic electrolyte might severely suffer from unwanted interfacial processes between the active materials and the ionic conductor. The dynamic properties of the ionic-electronic, that is, mixed conducting interphase (MCI) [1] formed are mostly unknown. Here, we used Li1.3Al0.3Ti1.7(PO4)3 (LATP) as a model electrolyte that is known to form an MCI when in contact with metallic Li or any other Li source. We prepared Li1.3+xAl0.3Ti1.7(PO4)3 with x = 0.2, 0.6 and 1.3 via ex situ chemical lithiation to mimic the formation of MCIs taking place otherwise operando. The preparation of large amounts of lithiated LATP with controlled Li contents allowed us to use nuclear and electric techniques to study local structures and ionic/electronic dynamics in detail. X-ray powder diffraction (XRPD), X-ray photoelectron spectroscopy (XPS), and 7Li, 27Al magic angle spinning nuclear magnetic resonance (NMR) point to the formation of a core-shell two-phase morphology with the Li-rich paramagnetic Li3Al0.3Ti1.7(PO4)3 phase covering the unlithiated Li-poor regions. Importantly, chronoamperometric polarization revealed an increase of the originally poor electronic conductivity σeon of 6.5 × 10−12 S cm−1 (293 K) by ca. 3 orders of magnitude, hence reaching the order of 6.6 × 10−9 S cm−1 if x = 0.6. At the same time, we observe a slight increase in bulk ion conductivity, which is also probed by 7Li NMR spin-lattice realxation measurements [2]. At even higher loadings (x = 1.3), a decrease in electronic (and ionic) conductivity is seen for Li3Al0.3Ti1.7(PO4)3, i.e., not exceeding alarming values for σeon. Our findings help understand the important interfacial side reactions in all-solid-state batteries. A detailed characterization of the two-phase system, including the separation of electronic and ionic transport processes, is essential to assess the severity of damage through MCI formation and to discuss whether any strategies to mitigate them are necessary at all.
We thank the FFG (safeLIB) and the DFG (WI 3600, NMR spectrometer) for financial support.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.